Corrugated materials are extremely useful because of their inexpensive cost and high strength compared to weight and their ability to be formed into finished materials ranging from boxes, spacers, structural elements etc. However, while corrugated cardboard is extremely useful it has several disadvantages. First, the appearance of the cardboard can be less then desirable. Second, the surface is rough and rigid and is prone to wrinkling. Third, while corrugated cardboard is relatively strong for its weight, it still lacks the needed support for heavy jobs tending to bend and pucker when placed under sideways pressure. Fourth, corrugated paper materials have little water resistance turn pulpy after exposure to moisture, whether ambient or direct.
Current technology used to corrugate includes the following process. In order to mold a medium into the required waveform, typically the medium gets pressed between two rollers that resemble wide gears. The teeth of the gears fit tightly together. When the medium is fed between the two rollers, the grooves force the medium into the desired waveform forming flutes. The frequency and amplitude of the waveform are determined by the frequency of grooves on the rollers and the depth of those grooves. Glue is often used to bond the corrugated layer to the flat layers. A different corrugating process is often used to corrugate metal and plastic sheeting where the flutes are oriented parallel to the direction of the material travel. The flutes are forced into the material by staggered rollers on the top and bottom of the material. Thus, corrugation of different substrates requires different types of technologies tailored to each substrate.
The limitations of the conventional corrugation process include: (1) The frequency and amplitude of the resulting wave are not easily adjustable, and certainly not in real time. This is because the exact frequency and amplitude of the wave are determined by the dimensions of the rollers used. In order to make any changes, the rollers must be swapped with a different set of rollers. This requires down time during the changeover. (2) Sets of rollers are expensive, therefore manufacturers typically have a limited number of them. This limits production to a set number of discrete frequencies and amplitudes. (3) This conventional method is well suited for smaller corrugations which have an amplitude in the range of ⅛th to ¼″. However, it becomes more difficult for larger corrugations in the range of 1″ up to several feet. Corrugation of larger amplitudes would require rollers that would be so big that it would be cost prohibitive. (4) The conventional method is well suited only for materials that will hold their shape after being molded by corrugating rollers. Typically paper must be heated and steam treated before corrugation so that it will hold its shape well. Materials with a low plasticity and high memory such as rubber or certain plastics may not hold their shape after going through corrugating rollers and therefore would be difficult to corrugate using conventional methods.
Therefore, a need exists for an apparatus and process that provides corrugated material that overcomes one or more of the current disadvantages noted above.